Eat Better Feel Better

Spring has sprung and flowers are blooming! This is the perfect time to venture outside and experience the emergence of a new season of growth. Many of you might be familiar with the idea that your diet affects your gut microbiome, which in turn affects your overall health. Do you also know that going outside and interacting with nature can positively influence your gut microbiome? The natural environment offers an abundance and diversity of beneficial microbes.^1-3 Interacting with nature provides the opportunity for beneficial microbes to establish in your gut, support your immune system, and help you become more resilient to inflammation and disease.^2-5 

There is a growing body of research showing that the environment around you influences the collection of microbes that inhabit different parts of your body, including your digestive system.^3,6 The environment may even contribute more to your microbiome than genetics.  Studies have found that unrelated individuals who share the same household or living environment have more similar gut microbiomes than related individuals who do not share a household.⁷ 

Scientists have theorized that the loss of biodiversity (variety of life) in our natural environment is one reason for the increases in inflammatory diseases.^3,8-11 Studies comparing populations from around the world have found higher gut bacterial species richness among people living in rural environments compared to those living in urban areas,^11-16 possibly because rural environments offer the opportunity to be exposed to greater biodiversity of living organisms compared to urban environments.^{2, 17-18} This may partly explain why inflammatory diseases conditions such as inflammatory bowel disease (IBD), type 1 diabetes, obesity, and psychiatric disorders have higher prevalence in urban environments and in high income countries with higher rates of development compared to rural and less urbanized countries.^3,18-19

Recent studies conducted in Finland have validated the positive influence of the natural environment on our microbiome and health. One study comparing the landscapes around the living environments of 48 elderly Finns (aged 65-79 years) found that higher numbers of shrub species in the yard around participants’ homes was associated with a healthier balance of gut bacteria species in their stool samples.²⁰ Similarly, having more plant species growing in the landscape around the home was found to be related to having greater diversity of bacteria on the skin among a sample of Finnish teenagers.⁹ And when comparing teenagers with and without atopic allergies, those without atopic allergies were more likely to live amongst greater environmental biodiversity.⁹

Researchers have also been exploring whether increasing our exposure and contact with natural environments, regardless of where we live, can support our microbiome. In a study involving daycare centers in Finland, adding sod and vegetation to the areas around daycare centers where children played was found to increase the richness and diversity of beneficial bacteria on children’s skin while lowering pathogenic bacteria.²¹ In addition, experimental studies have demonstrated that rubbing the hands with soil and plant material increases beneficial microbial diversity in the gut²² and skin.²³ Therefore, increasing our contact and exposure to nature is a promising way to improve the balance of our microbiome, and subsequently improve our health.

With the days becoming longer, now is the perfect time to catch all the beneficial microbes you can from nature. If you live in an unpolluted environment, just being outside, breathing fresh air, and exposing your body to the outdoors can benefit your gut microbiome. If you live in an urban environment, consider spending more time in the parks, or taking a trip to hike in a forest. Grow a garden. Hug a tree. Swim in the ocean. Take advantage of the infinite possibilities for interacting with nature, and your microbiome will thank you.

Dandelion flower tea

Ingredients:

• A big handful of dandelion flowers
• Hot water
• Raw honey (optional)

Instructions:

1. Pick a handful of blooming, yellow dandelion flowers from an unpolluted area. It’s best to pick them in the middle of a sunny day when the flowers are open and dry. 
2. Examine the flowers for bugs and debris and clean them by blowing or shaking off any bugs or debris. 
3. Using your fingers, gently pull out the yellow petals from the base of the flower and stem. Place the yellow flower petals in a mug, heat resistant jar, or tea pot.
4. Boil water. Pour hot water over the flower petals. Steep for 5 minutes. Strain, and enjoy the tea. Add raw honey if you prefer sweetened tea. 

You can adjust the strength of the tea to your liking with less or more flower petals. Steep your tea for longer if you want a stronger flavor. If you are feeling adventurous, you can harvest the dandelion root too and add it to your tea, and add dandelion leaves to your salads. Dandelion leaves are rich in vitamins A, C, E, K, and minerals including calcium, potassium, iron, and zinc.²⁴ The dandelion has many medicinal properties, including being antiinflammatory, anticancer, diuretic, and protective of the liver.²⁵

References:

1. Nielsen CC, Gascon M, Osornio-Vargas AR, Shier C, Guttman DS, Becker AB, Azad MB, Sears MR, Lefebvre DL, Moraes TJ, Turvey SE. Natural environments in the urban context and gut microbiota in infants. Environment International. 2020.142:105881. 
2. Flies EJ, Clarke LJ, Brook BW, Jones P. Urbanization reduces the abundance and diversity of airborne microbes-but what does that mean for our health? A systematic review. Science of the Total Environment. 738:140337.
3. Haahtela T. A biodiversity hypothesis. Allergy. 2019. 74(8):1445-56.
4. Robinson JM, Mills JG, Breed MF. Walking ecosystems in microbiome-inspired green infrastructure: an ecological perspective on enhancing personal and planetary health. Challenges. 2018. 9(40):1-15.
5. Mills JG, Brookes JD, Gellie NJ, Liddicoat C, Lowe AJ, Sydnor HR, Thomas T, Weinstein P, Weyrich LS, Breed MF. Relating urban biodiversity to human health with the ‘holobiont’ concept. Frontiers in Microbiology. 2019. 10(550):1-8.
6. Phillips ML. Gut reaction: environmental effects on the human microbiota. Environmental Health Perspectives. 2009. 117(5):1-8.
7. Rothschild D, Weissbrod O, Barkan E, Kurilshikov A, Korem T, Zeevi D, Costea PI, Godneva A, Kalka IN, Bar N, Shilo S. Environment dominates over host genetics in shaping human gut microbiota. Nature. 2018. 555(7695):210-5.
8. von Hertzen L, Hanski I, and Haahtela T. Natural immunity. Biodiversity loss and inflammatory diseases are two global megatrends that might be related. EMBO Rep. 2011.12:1089–1093. doi: 10.1038/embor.2011.195
9. Hanski I, von Hertzen L, Fyhrquist N, Koskinen K, Torppa K, Laatikainen T, Karisola P, Auvinen P, Paulin L, Mäkelä MJ, Vartiainen E. Environmental biodiversity, human microbiota, and allergy are interrelated. Proceedings of the National Academy of Sciences. 2012. 109(21):8334-9. doi: 10.1073/pnas.1205624109
10. Mosca A, Leclerc M, Hugot JP. Gut microbiota diversity and human diseases: should we reintroduce key predators in our ecosystem? Frontiers in Microbiology. 2016. 7(455):1-11.
11. Tasnim N, Abulizi N, Pither J, Hart MM, Gibson DL. Linking the gut microbial ecosystem with the environment: does gut health depend on where we live? Frontiers in Microbiology. 2017. 8(1935):1-8.
12. Martínez I, Stegen JC, Maldonado-Gómez MX, Eren AM, Siba PM, Greenhill AR, Walter J. The gut microbiota of rural papua new guineans: composition, diversity patterns, and ecological processes. Cell Reports. 2015. 11(4):527-38.
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14. Schnorr SL, Candela M, Rampelli S, Centanni M, Consolandi C, Basaglia G, Turroni S, Biagi E, Peano C, Severgnini M, Fiori J. Gut microbiome of the Hadza hunter-gatherers. Nature communications. 2014.5(1):1-2.
15. De Filippo C, Cavalieri D, Di Paola M, Ramazzotti M, Poullet JB, Massart S, Collini S, Pieraccini G, Lionetti P. Impact of diet in shaping gut microbiota revealed by a comparative study in children from Europe and rural Africa. Proceedings of the National Academy of Sciences. 2010.107(33):14691-6.
16. Ayeni FA, Biagi E, Rampelli S, Fiori J, Soverini M, Audu HJ, Cristino S, Caporali L, Schnorr SL, Carelli V, Brigidi P. Infant and adult gut microbiome and metabolome in rural Bassa and urban settlers from Nigeria. Cell Reports. 2018.23(10):3056-67.
17. Blum WE, Zechmeister-Boltenstern S, Keiblinger KM. Does soil contribute to the human gut microbiome? Microorganisms. 2019.7(287):1-16.
18. Haahtela T, Holgate S, Pawankar R, Akdis CA, Benjaponpitak S, Caraballo L, Demain J, Portnoy J, von Hertzen L. The biodiversity hypothesis and allergic disease: world allergy organization position statement. World Allergy Organization Journal. 2013.6(3):1-18.
19. Rook GA, Lowry CA, Raison CL. Microbial ‘Old Friends’, immunoregulation and stress resilience. Evolution, Medicine, and Public Health. 2013.1:46-64.
20. Parajuli A, Hui N, Puhakka R, Oikarinen S, Grönroos M, Selonen VA, Siter N, Kramna L, Roslund MI, Vari HK, Nurminen N. Yard vegetation is associated with gut microbiota composition. Science of the Total Environment. 2020.713:1-8.
21. Roslund MI, Puhakka R, Nurminen N, Oikarinen S, Siter N, Grönroos M, Cinek O, Kramná L, Jumpponen A, Laitinen OH, Rajaniemi J. Long-term biodiversity intervention shapes health-associated commensal microbiota among urban day-care children. Environment International. 2021.157:106811.
22. Nurminen N, Lin J, Grönroos M, Puhakka R, Kramna L, Vari HK, Viskari H, Oikarinen S, Roslund M, Parajuli A, Tyni I. Nature-derived microbiota exposure as a novel immunomodulatory approach. Future Microbiology. 2018.13(7):737-44.
23. Grönroos M, Parajuli A, Laitinen OH, Roslund MI, Vari HK, Hyöty H, Puhakka R, Sinkkonen A. Short‐term direct contact with soil and plant materials leads to an immediate increase in diversity of skin microbiota. Microbiology Open. 2019. 8(3):e00645.
24. Lis B, Olas B. Pro-health activity of dandelion (Taraxacum officinale L.) and its food products–history and present. Journal of Functional Foods. 2019. 59:40-8.
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